Municipality of the department of Valle del Cauca, considered the wine capital of Colombia, and unlike most cities in the Valley, a large amount of all kinds of tropical fruits are grown there, such as grapes, papaya, passion fruit, lulo, cocoa, coffee, guava, among others; thanks to this, its urban development has been faster than that of other Valle del Cauca towns because its horticultural axis is not centered on sugar cane, unlike 80% of the entire department.
The other name as it was known in the past was Hato de Lemos, since the lands where this municipality was built were owned by the landowner Pedro Lemos. It was founded on April 20, 1796 but became a municipality in 1890 and its founder was called Juan Jacinto Palomino.
The Gorrones Indians, who prevailed on the western bank of the Cauca River, from Cali to Anserma, were the first inhabitants of La Unión, Valle. Its name comes from the name of the fish that was an important food in its gastronomy. La Unión was the scene of the most important social protest during the colonial period against Spanish authority in the west of the viceroyalty of New Granada, an episode known as the Uprising of Hato de Lemos in 1781. It has a large number of vineyards and is the main headquarters of the Casa Grajales Winery and the Museum of Grapes and Wine. Extreme sports such as paragliding and motorcycling are also practiced.